AbstractA diagnosis of the life cycles of three South Pacific cyclones, each tropical in origin, is presented. the study focuses on two of the cyclones which propagate south‐eastward along the western edge of the South Pacific convergence zone (SPCZ) and reach middle latitudes before decaying. Based on enhanced IR satellite imagery from GOES‐West, both cyclones appear to go through stages of development similar to those described by Troup and Streten, even though their classification system generally applies to higher latitude systems. the primary data set used for surface and upper air analyses is based on ECMWF FGGE level III‐b analyses. Variables presented include mean sea level pressure (m.s.l.p.), horizontal divergence, relative vorticity, and winds. A comparison between m.s.l.p. patterns obtained manually from station observations and those produced objectively by ECMWF shows good agreement except when the cyclonic disturbances are subgrid‐scale. Maximum low level convergence occurs in the SPCZ, north and east of the cyclone tracks; however, maxima of low level cyclonic vorticity correspond to the individual cyclones. Cyclone tracks appear to be influenced by the upper level subtropical jet. the two cyclones which propagate into middle latitudes are accompanied by lower tropospheric warm (cold) air advection ahead of (behind) the system. Both cyclones also exhibit upper tropospheric anticyclonic (cyclonic) vorticity ahead of (behind) the